Tiger was included with all new Macs, and was also available as an upgrade for existing Mac OS X users, or users of supported pre-Mac OS X systems. The server edition, Mac OS X Server 10.4, was also available for some Macintosh product lines. Six weeks after its official release, Apple had delivered 2 million copies of Tiger, representing 16% of all Mac OS X users. Apple claimed that Tiger was the most successful Apple OS release in the company's history.[6] At the WWDC on June 11, 2007, Apple's CEO, Steve Jobs, announced that out of the 22 million Mac OS X users, more than 67% were using Tiger.[7]

Tiger was succeeded by Mac OS X Leopard on October 26, 2007, after 30 months, making Tiger the longest running version of Mac OS X.[9] The last security update released for Tiger users was the 2009-005 update.[10][11] The next security update, 2009-006[12] only included support for Leopard and Snow Leopard. The latest supported version of QuickTime is 7.6.4. The latest version of iTunes that can run on Tiger is 9.2.1, because 10.0 only supports Mac OS X Leopard and later.[13] Safari 4.1.3 is the final version for Tiger as of November 18, 2010.[14] Despite not having received security updates since then, Tiger remains popular with Power Mac users and retrocomputing enthusiasts due to its wide software and hardware compatibility, as it runs on a wide variety of older machines and is the last OS X version that supports Classic Environment, a Mac OS 9 compatibility layer.[15]

Tiger was initially available in a PowerPC edition, with an Intel edition released beginning at 10.4.4. There is no universal version of the client operating system, although Tiger Server was made available on a universal DVD from version 10.4.7. While Apple shipped the PowerPC edition bundled with PowerPC-based Macs and also sold it as a separate retail box, the only way to get the Intel version was bundled with an Intel-based Mac. However, it was possible to buy the ‘restore’ DVDs containing the Intel version through unofficial channels such as eBay, and officially through Apple if you could provide proof of purchase of the appropriate Intel Mac. These grey colored ‘restore’ DVDs supplied with new Macs, are designed to only restore on the model of Mac that they are intended for. The retail PPC-only DVD can be used on any PPC-based Mac supported by Tiger.

Tiger removed support for older New World ROM Macs such as the original iMacs and iBooks that were supported in Panther; however it is possible to install Tiger on these Macs using third-party software (such as XPostFacto) that overrides the checks made at the beginning of the installation process. Likewise, machines such as beige Power Mac G3s and ‘Wall Street’ PowerBook G3s that were dropped by Panther can also be made to run both Panther and Tiger in this way. Also, Tiger can be installed on unsupported New World ROM Macs by installing it on a supported Mac, then swapping hard drives. Old World ROM Macs require the use of XPostFacto to install Tiger.

Tiger was the last version of Mac OS X that supported the PowerPC G3 processor.

Apple CEO Steve Jobs first presented Tiger in his keynote presentation at the WWDC on June 28, 2004, ten months before its commercial release in April 2005. Four months before that official release, several non-commercial, developer's releases of Tiger leaked onto the internet via BitTorrent file sharers. It was first mentioned on Apple's website on May 4, 2004. Apple sued these file sharers.[17] On April 12, 2005, Apple announced Tiger's official, worldwide release would be April 29. All Apple Stores around the world held Tiger seminars, presentations and demos.

On June 6, 2005 at the WWDC in San Francisco, Jobs reported that nearly two million copies had been sold in Tiger's first six weeks of release, making Tiger the most successful operating system release in Apple's history. Jobs then disclosed that Mac OS X had been engineered from its inception to work with Intel's x86 line of processors in addition to the PowerPC, the CPU for which the operating system had always been publicly marketed. Apple concurrently announced its intent to release the first x86-based computers in June 2006, and to move the rest of its computers to x86 microprocessors by June 2007. On January 10, 2006, Apple presented its new iMac and MacBook Pro computers running on Intel Core Duo processors, and announced that the entire Apple product line would run on Intel processors by the end of 2006. Apple then released the Mac Pro and announced the new Xserve on August 8, completing the Intel transition in 210 days, roughly ten months ahead of the original schedule.

Tiger is the first version of Mac OS X to be supplied on a DVD, although the DVD could originally be exchanged for CDs for $9.95. It is also the first (and so far only) version of Mac OS that would eventually have an update version number ending with a value greater than 9, as the last version of Tiger was 10.4.11.

Apple advertises that Tiger has over 150 new and improved features, including:

Spotlight — Spotlight is a full-text and metadata search engine, which can search everything on one's Mac including Microsoft Word documents, iCal calendars and Address Book contact cards. The feature is also used to build the concept of ‘smart folders’ into the Finder. Spotlight will index files as they are saved, so they can be quickly and easily found through a search-as-you-type box in the menu bar. As a side-effect, it adds hidden folders and indexing files to removable media like USB flash drives.

iChat AV — The new iChat AV 3.0 in Tiger supports up to four participants in a video conference and ten participants in an audio conference. It also now supports communication using the XMPP protocol. A XMPP server called iChat Server is included on Mac OS X Tiger Server.

Safari RSS — The new Safari 2.0 web browser in Tiger features a built-in reader for RSS and Atomweb syndication that can be accessed easily from an RSS button in the address bar of the web browser window. An updated version of Safari, included as part of the free Mac OS X v.10.4.3 update, can also pass the Acid2 web standards test.

Mail 2 — The new version of Mail.app email client included in Tiger featured an updated interface, "Smart Mailboxes" which utilize the Spotlight search system, parental controls, as well as several other features.

The Dashboard allows for miniature applications called "Widgets" to appear and disappear rapidly from the screen.

Dashboard — The Dashboard is a new mini-applications layer based on HTML, CSS, and JavaScript, which returns the desk accessories concept to the Mac OS. These accessories are known as widgets. It comes with several widgets such as Weather, World Clock, Unit Converter, and Dictionary/Thesaurus. More are available for free online. Its similarity to the Konfabulator application caused some criticism.[18]

Automator — A scripting tool to link applications together to form complex automated workflows (written in AppleScript, Cocoa, or both). Automator comes with a complete library of actions for several applications that can be used together to make a Workflow.

VoiceOver — accessibility interface that offers the user magnification options, keyboard control and spoken English descriptions of what is happening on screen. VoiceOver enables users with visual impairment the ability to use applications via spoken commands. It also allows a user to work collaboratively with other users on a single Mac by allowing multiple users give voice commands to scroll text, etc. VoiceOver is capable of reading aloud the contents of files including web pages, mail messages and word processing files. The complete keyboard navigation lets the user control the computer with the keyboard rather than mouse, a menu is displayed in a window showing all the available keyboard commands that can be used.

.Mac syncing — Though this is not a new feature, .Mac syncing in Tiger is much improved over Panther. Syncing tasks in Tiger are now accomplished through the .Mac system preferences pane rather than the iSync application.

QuickTime 7 — A new version of Apple's multimedia software has support for the new H.264/AVC codec which offers better quality and scalability than other video codecs.[citation needed] This new codec is used by iChat AV for clearer video conferencing. New classes within Cocoa provide full access to QuickTime for Cocoa application developers. The new QuickTime 7 player application bundled with Tiger now includes more advanced audio and video controls as well as a more detailed Information dialog, and the new player has been rebuilt using Apple's Cocoa API to take advantage of the new technologies more easily.

New Unix features — New versions of cp, mv, and rsync which support files with resource forks. Command-line support for features like the above-mentioned Spotlight are also included.

Dictionary — A dictionary and thesaurus program which uses the New Oxford American Dictionary. It has a fast GUI for displaying the Dictionary, and allows the user to search the dictionary with Spotlight, to print definitions, and to copy and paste text into documents. Dictionary also provides a Dictionary service in the Application menu, and Cocoa and WebKit provides a global keyboard shortcut (ctrl-⌘-D by default) for all applications that display text with them. Its use was furthered in the next version of OS X by providing definitions from Wikipedia. The Dictionary application is a more feature-filled version of the Dictionary widget.

Quartz Composer — Quartz Composer is a development tool for processing and rendering graphical data.

An updated libSystem with both 32-bit and 64-bit versions; combined with the aforementioned kernel change, this allows individual applications to address more than 4 GB of memory when run on 64-bit processors, although an application using Apple libraries or frameworks other than libSystem would need to have two processes, one running the 64-bit code and one running the code that requires other libraries and frameworks.[19][20]

The printing dialog in Tiger now features a drop down menu for creating PDFs, sending PDFs to Mail, and other PDF related actions. However, the user interface has been criticized for creating a hybrid widget that looks like a plain button but acts like a pop-up menu. This is one of only three places in the entire Mac OS X interface where such an element appears.

Dock menus now have menu items to open an application at login, or to remove the icon from the dock.

The Window menu in the Finder now features a "Cycle Through Windows" menu item.

The Get Info window for items in the Finder now includes a "More Info" section that includes Spotlight information tags such as Image Height & Width, when the file was last opened, and where the file originated.

Early development of resolution independence. Apple notes that this will be a user-level feature in a future version of Mac OS X.[21] Among the changes, the maximum size of icons has been increased to 256x256. However, the Finder does not yet support this size.

In every major new revision of Mac OS X, Apple alters the graphical user interface somewhat. In Tiger, the menu bar displayed at the top of the screen now features a colored Spotlight button in the upper right corner; the menu itself has a smoother 'glassy' texture to replace the faint pinstripes in Panther.

Also of note, Tiger introduces a new window theme, often described as 'Unified'. A variation on the standard, non-brushed metal theme used since the introduction of Mac OS X, this theme integrates the title bar and the toolbar of a window. A prominent example of an application that utilizes this theme is Mail.

Apple Computer's use of its infringing family of Tiger marks to expand sales of products besides its operating system software is already evident — for example, Apple Computer is offering free iPods and laptops as part of its Tiger World Premiere giveaway. In short, notwithstanding its representation to the PTO that it would only use Tiger in connection with their unique computer operating system software, Apple Computer has in recent weeks used a family of Tiger marks in connection with a substantially broader group of products and services, including the very products and services currently offered by Tiger Direct under its famous family of Tiger marks.[23]

In 2005 TigerDirect was denied a preliminary injunction which would have prevented Apple from using the mark while the case was decided.[24] Apple and TigerDirect reached a settlement in 2006, after which TigerDirect withdrew its opposition.[25]

At the 2005 WWDC, Apple CEO Steve Jobs announced that Apple would begin selling Mac computers with Intel processors in 2006. To allow developers to begin producing software for these Intel-based Macs, Apple made Developer Transition Kits available for sale which included a version of Mac OS X v10.4.1 designed to run on x86 processors.

This build includes Apple's Rosetta — a translation process that allows Intel processor versions of the OS to run PPC software with little penalty. This is contrasted with the current Mac OS 9 Classic mode, which uses comparably larger amounts of system resources.

Soon after the Developer Transition Kits began shipping, copies of Tiger x86 were leaked onto file sharing networks. Although Apple had implemented a Trusted ComputingDRM scheme in the transition hardware and OS in an attempt to stop people installing Tiger x86 on non-Apple PCs, the OSx86 project soon managed to remove this restriction.[26] As Apple released each update with newer safeguards to prevent its use on non-Apple hardware, unofficially-modified versions were released that circumvented Apple's safeguards. However, with the release of 10.4.5, 10.4.6, and 10.4.7 the unofficially-modified versions continued to use the kernel from the 10.4.4 because later kernels have hardware locks and depend heavily on EFI. By late 2006, the 10.4.8 kernel was cracked.[27]

At MacWorld San Francisco 2006, Jobs announced the immediate availability of Mac OS X v10.4.4, the first publicly available release of Tiger compiled for both PowerPC and Intel x86 based machines.